1. Field
The present disclosure relates generally to sound processors such as, for example, the sound processors in implantable cochlear stimulation (or “ICS”) systems.
2. Description of the Related Art
ICS systems are used to help the profoundly deaf perceive a sensation of sound by directly exciting the intact auditory nerve with controlled impulses of electrical current. Ambient sound pressure waves are picked up by an externally worn microphone and converted to electrical signals. The electrical signals, in turn, are processed by a sound processor, converted to a pulse sequence having varying pulse widths and/or amplitudes, and transmitted to an implanted receiver circuit of the ICS system. The implanted receiver circuit is connected to an implantable electrode array that has been inserted into the cochlea of the inner ear, and electrical stimulation current is applied to varying electrode combinations to create a perception of sound. A representative ICS system is disclosed in U.S. Pat. No. 5,824,022, which is entitled “Cochlear Stimulation System Employing Behind-The-Ear Sound processor With Remote Control” and incorporated herein by reference in its entirety.
As alluded to above, some ICS systems include an implantable device, a sound processor with sound processing circuitry, and a microphone that is in communication with the sound processor. The implantable device communicates with the sound processor and, to that end, some ICS systems include a headpiece that is in communication with both the sound processor and the implantable device. In one type of ICS system, the sound processor is worn behind the ear (or “BTE”) sound processor, while other types of ICS systems have a body worn sound processor. The body worn sound processor, which is larger and heavier than a BTE sound processor, is typically worn on the user's belt or carried in the user's pocket. One example of a conventional body worn sound processor is the Advanced Bionics Platinum Series body worn sound processor.
Sound processors include various control structures that may be employed by the user to control certain operational parameters (e.g. a volume knob, a sensitivity knob and/or a program selector knob). The control structures are mechanically connected, by way of openings in the sound processor housing, to structures within the housing so that movement of the control structure (e.g. rotation of a knob) can be detected and the associated operational parameter adjusted accordingly. The openings in the sound processor housing for the mechanical connections necessitate the use of seals to prevent the ingress of liquid, dust, and other contaminants. The present inventor has determined that, despite the use of seals, such control structures can be the source of leaks and other kinds of contamination.